The standard TOS grants: " a royalty-free, sublicensable, transferable, perpetual, irrevocable, non-exclusive, worldwide license to use, reproduce, modify, publish, list information regarding, edit, translate, distribute, publicly perform, publicly display, and make derivative works of all such User Content and your name, voice, and/or likeness ..." Emphasis added. Non-exclusive, which means you can use it elsewhere. But goodreads could bundle & sell reviews if they wanted. I don't see any indication that they could prevent a reviewer from publishing their own content elsewhere, although there doesn't seem to be any requirement that they remove reviews at the reviewer's request. Their TOU for writers requires: "a royalty-free, sublicensable (solely as required to publish the Work in connection with the Service), transferable (solely to a successor to Goodreads’ business), revocable, non-exclusive, worldwide license to use, reproduce, publish, list information regarding, edit, translate, distribute, publicly perform, publicly display, and (for formatting purposes or to conform to system requirements only) modify and make derivative works of the Work and your name, voice, and/or likeness in connection with the Work"...